Trophotropic response system

ABSTRACT

A trophotropic response system which aids a user in achieving a relaxation response. In one embodiment the system includes a control unit and an audio-visual unit. The control unit includes a processor and associated hardware and software to control the audio-visual unit. The audio-visual unit includes a light producing unit having a pair of earphones coupled thereto. The light producing unit includes a plurality of light sources which direct light toward a diffuser screen disposed between the eyes of a user and the light sources. This arrangement permits the user to see light from the light sources diffused over a large visual angle. The light sources produce light and the earphones produce sound in response to audio and light control signals provided by the processor of the control unit. The signal characteristics of the light and sound control signals may be varied within predefined limits to aid the user in performing a relaxation exercise.

FIELD OF THE INVENTION

The invention relates to apparatus and methods of relaxation in generaland audio-visual devices for providing an environment conducive toelicitation of a relaxation response in particular.

BACKGROUND OF THE INVENTION

In the presence of stress, the autonomic nervous system of a human bodycauses a variety of physiological changes in the human body. Suchchanges may include, for example, an increase in heart rate andrespiration rate, suppression of digestive activity, tensing of musclesand constriction of blood vessels. These physiological changes inresponse to stress are collectively referred to as the ergotrophicresponse or the "fight or flight" response. This response has evolved inhumans in order to prepare the body for self-protection in the face of aphysical threat.

In modern society, however, most sources of stress are not the result ofimpending physical danger but rather result from the continual exposureto daily stressors, such as deadlines and commitments. As a result ofthe continuous exposure to such stressors, the body is subjected toundue strain resulting in a decrease in performance.

To reduce this ergotrophic response, it is necessary to cause the bodyto relax or undergo a trophotropic or relaxation response. A bodyundergoing a trophotropic response reduces its heart and respirationrate, relaxes its muscles, and dilates its blood vessels therebyresulting in a lowering of its blood pressure. In this relaxed state,the cognitive efficiency of the person is increased.

In recent years relaxation techniques such as meditation, yoga,autogenic training and electronic biofeedback devices have aidedindividuals in achieving the relaxation response. Each of thesetechniques has attributes and deficiencies associated with it, and so,has its adherents and its detractors. The present invention relates to adevice which aids the user in obtaining the relaxation response.

SUMMARY OF THE INVENTION

A trophotropic response system includes a control module for providing avisual signal and an aural signal having an ocean signal component and abinaural beat signal component. The trophotropic response system furtherincludes an audio unit for receiving the aural signal from the controlmodule and a visual unit for receiving the visual signal from thecontrol module wherein the visual signal is provided having a frequencycorresponding to the frequency of the binaural beat component of theaural signal. With this particular arrangement a trophotropic responsesystem for aiding a user in obtaining a relaxation response is provided.The audio unit and visual unit may be coupled to a frame and provided asan integral part thereof. The control module may include a microcomputersubsystem for providing the visual signal and the aural signal, adisplay driver coupled to said microcomputer subsystem and a display,coupled to the display driver, for displaying information provided fromthe microcomputer system. The visual unit may include a visor havingfirst and second opposing surfaces, coupled to the frame and a diffuserscreen, having first and second opposing surfaces, wherein the diffuserscreen is also coupled to the frame and arranged such that a firstsurface thereof is disposed proximate a first surface of the visor. Atleast one light source may be coupled to the visor and disposed toproject light onto the diffuser screen. In a preferred embodiment, thelight source may include a plurality of light sources each of which aredisposed between the visor and the diffuser screen and which projectlight onto the diffuser screen. The light sources may be provided forexample as light emitting diodes which may emit either a single colorlight or a plurality of different colors of light. The aural signal mayinclude a pair of binaural beat signal components each having asinusoidal characteristic. A first binaural beat signal component havinga frequency in a first frequency range may be provided on a left channelof the audio unit and a second binaural beat signal component having avarying frequency equal to the left channel frequency plus the binauralbeat frequency may be provided on a right channel of the audio unit. Theocean signal component of the aural signal may correspond to pink noisemodulated by a pair of envelope signals wherein the pink noise in eachchannel is generated separately but is provided having the sameamplitude. Pink noise is a particular spectrum of noise in which highfrequency components are reduced in amplitude and low frequencycomponents are increased in amplitude in a linear ramp. It should benoted that other types of noise may of course also be used. The visualsignal may be provided from a sinusoidal signal and a rectangular wavesignal. The sinusoidal signal may be provided having a firstpredetermined frequency and the rectangular wave signal may be providedhaving a predetermined duty cycle wherein the duty cycle of therectangular wave signal increases linearly from a first duty cycle at afirst predetermined frequency to a second different duty cyclecorresponding to the predetermined duty cycle at a second predeterminedfrequency.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of an embodiment of the control module of theinvention;

FIG. 2 is a right side view of the embodiment of the control module ofthe invention of FIG. 1;

FIG. 3 is a left side view of the embodiment of the control module ofthe invention of FIG. 1;

FIG. 4 is a back view of the embodiment of the control module of theinvention of FIG. 1;

FIG. 5 is a front view of the embodiment of the control module of theinvention of FIG. 1;

FIG. 6 is a bottom view of the embodiment of the control module of theinvention of FIG. 1;

FIG. 7 is a perspective view of an embodiment of the audio-visual moduleof the invention;

FIG. 8 is an exploded view of the embodiment of the audio-visual moduleof FIG. 7;

FIG. 9 is a block diagram of an embodiment of the system of theinvention;

FIG. 10 is a circuit level functional diagram of the embodiment of thesystem of FIG. 9;

FIG. 11 is a schematic diagram of the microprocessor portion of anembodiment of the system of FIG. 9;

FIG. 12 is a schematic diagram of the audio portion of an embodiment ofthe system of FIG. 9;

FIG. 13 is a schematic diagram of the video portion of an embodiment ofthe system of FIG. 9; and

FIGS. 14-14D are a series of high level flow diagrams of the processingperformed by the microcomputer subsystem of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1-7 and in brief overview, a trophotropicresponse system 9 includes a control module 10 (FIGS. 1-6) and anaudio-visual module 12 (FIG. 7). Control module 10 is coupled toaudio-visual 12 via a cable 13. The control module 10, in oneembodiment, includes a liquid crystal display (LCD) 20, a temperaturesensor 22 and a series of controls, including a sound intensity control24, a light intensity control 26, and a keypad 28. The keypad 28includes a series of buttons used to control the functioning of thesystem. These buttons include a POWER (on/off) button 30, a START button32, an END button 34, a TIME button 36 and an initiate or GO button 38.The function of each of the controls will be described in detail below.The liquid crystal display 20, keypad 28 and controls 24, 26 areincorporated into a resilient plastic housing 40 which also incorporatesthe electronics and power supply for the system 9.

The liquid crystal display 20 is here provided as a 79 segment customdisplay that is used to display vertical bar graphs of: the startingfrequency of the light and sound generated by the audio-visual unit 12,the ending frequency of the light and sound generated by theaudio-visual module 12, the time duration of the session, and the fingertemperature of a user. Three additional segments are used to indicatelow battery conditions, manual mode, and "AFR" mode. Those of ordinaryskill in the art will now recognize of course that other information mayalso be displayed. For example, display 20 may display any of thephysiological indications such as heart rate, muscle tension, brainwave,skin conductance, or any other physiological indicator known to one ofordinary skill in the art.

The audio-visual module 12 (FIGS. 7 and 8) in one embodiment is providedas a set of goggles having a video unit 42 and an audio unit 44. Theaudio unit 44 includes a set of stereo-earphones 46 each of which isattached to the frame 48 of the goggles by an adjustable mounting arm50. Mounting arm 50 may be moved back forth along frame 48 to adjust tothe size of the users head. A first end of cable 13 may be coupled tocontrol module 10 via a so-called MICRO-DIN connector. A second end ofcable 13 is bifurcated. Each bifurcated cable section is coupled to acorresponding one of the stereo earphones 46 The video unit 42 isconstructed as an opaque visor 52 upon which are disposed a plurality oflight sources 54. The light sources 54 are here provided as lightemitting diode (LEDs) lamps 54a-54d, disposed over a first surface ofand toward the edges of the visor 52. Although four LEDs are here shown,it may, in some applications, be advantageous to use fewer than four ormore than four light sources. The particular number of light sources maybe selected according to a variety of factors including but not limitedto the environment which is to be provided to the user. Thus while audiovisual module 12 may include only a single light source preferredembodiments use at least two light sources per eye.

In the case where only a single LED is used the LED may appear as apoint source to a user. Thus to minimize the appearance of the lightsource as a point source, an additional layer in the diffusion screenmay be required.

It should be noted that light sources 54 may be positioned along anyportion of visor 52. If LEDs 54 are spaced a relatively large distancefrom the center of visor 52, it is possible to position the LEDs suchthat an environment is provided for only one side of the brain. Thus, ifLEDs 54 were disposed close to the temple 50 and only one pair of LEDswere periodically illuminated then the opposite side of the brain onwhich the LEDs were excited will be subject to the environment providedby the system 12.

It should be also noted however, that an increase in the number of lightsources 54 which are disposed on visor 52 provides a concomitantincrease in the color variations which may be provided through the LEDsand also provides a greater flexibility in the positioning of particularones of the LEDs. That is, the LEDs may be disposed in differentlocations and provide a different light field to the user. Furthermore,light sources 54 need not be provided as light emitting diodes but couldalso be provided from fiber optic rods, for example, fed through thegoggles and disposed to emit light as desired. Here, LEDs 54 projectlight onto a diffuser screen 56 having a generally translucentappearance and a thickness typically of about 0.5 mm. Diffuser screen 56may be provided for example from calendered "LEXAN" (polycarbonateresin) and is positioned between the LEDs 54 and the eyes of the user. Apolyester foam spacer 53 having a thickness typically of about 0.375inch separates diffuser screen 56 from visor 52. Spacer 53 providesclearance between the visor 52 and the diffuser screen 56 for the LEDs54. The thickness of spacer 53 should be selected such that the lightemitted from LEDs 54 is properly diffused by the diffusion screen. Thatis, the light is diffused by diffusion screen 56 such that substantiallyno point sources of light are visible to a user.

LEDs 54 in the present embodiment are provided as red-light emittingGallium Astatime Arsenide (GaAtAs) super-luminosity LED lampsmanufactured by Sharp Electronics. Other types of LEDs may also be used.For example, Gallium Aluminum Arcinide (GaAlAs) LEDs which are veryefficient in terms of brightness may also be used. It should be notedthat the LEDs 54 should provide a relatively bright light and should beresponsive to signals fed thereto. Consequently GaAlAs LEDs may beparticularly useful in the present invention since they generallyprovide a relatively bright light for a particular LED size. Thus, inthis particular embodiment it is desirable to use LEDs which provide arelatively bright light in a relatively small package size.

It should also be noted that LEDs 54a-54d may be provided as multicolorLEDs which emit a plurality of different color light or even acontinuous range of colors within a predetermined band of the visiblelight spectrum. Moreover, in some embodiments it may be desirable to usea two color LED of the type manufactured by SHARP and identified as partnumber GL3UR8. Other commercially available LED lamps having similarpackage sizes and electrical characteristics may also be used.

Diffuser screen 56 diffuses the light emitted from the LEDs 54 over alarge visual angle. The diffuser screen 56 is provided having athickness typically in the range of about 0.010 inch to 0.015 inch andmay be provided for example from a translucent plastic material. Aninner polyester foam pad 58 having a thickness typically of about 0.25inches is located along the inner top surface of the diffuser screen 56to provide a padded surface to rest against the forehead of the user.

The LED's 54 and earphones 46 produce light and sound, respectively, inresponse to signals fed thereto from control module 10. By adjusting thesound intensity 24 and light intensity 26 controls of the control module10, the intensity of the light from the LEDs 54 and the volume of thesound produced by the earphones 46, respectively, may be varied to suitthe individual user.

It should also be noted that in some embodiments a sensor for measuringa physiological characteristic of a user, may be disposed on the gogglessuch that the sensor contacts a predetermined region of the user. Forexample, such a sensor may contact a portion of the users head such asthe user's face. In addition to a temperature sensor, the sensor may beprovided as any type of sensor including but not limited to a muscletension sensor, a heart rate sensor, an electro dermal resistance (EDR)sensor or an EMG sensor.

In general, the audio signal generated by the earphones 46 has a pinknoise or "ocean" background component and a binaural beat component. Thebinaural beat component of the sound may be generated by providing anaudio signal having a first frequency, for example 100 Hz in a first oneof the earphones 46, and providing an audio signal having in the otherearphone 46 a second frequency equal to the first frequency plus thebinaural beat frequency. Thus, as the binaural beat frequency ischanged, the frequency of the audio signal in the second earphone 46changes accordingly.

The ocean sound component is provided as a stereo signal and providesthe user with a sensation of motions in the left to right and front toback directions. Thus, the ocean signal component closely emulates thesound provided by the actual ocean.

The ocean signal component is generated via the microprocessor as willbe described further below in conjunction with FIGS. 14-14D.Furthermore, the ocean sound component may be synchronized with otherstimulus provided to the user including the light signals from lightsources 54 and the binaural beat frequency signals. Thus, when the lightsource emits light at a frequency in the beta frequency range typicallyof about 20 Hz the frequency of the ocean sound has a correspondingincrease. However, when the frequency of the light signal is in thealpha frequency range for example, the frequency of the ocean signalcomponent is reduced. Thus, the system provides an optimum environmentin aiding the user to achieve the trophotropic response.

The starting binaural beat frequency may be set by the user by pressingthe START button 32 (FIG. 1) repeatedly until the desired startingbinaural beat frequency is displayed on the LCD display 20. The endingbinaural beat frequency may similarly be set by pressing the END button34 (FIG. 1) repeatedly. Similarly, by pressing the TIME button 36(FIG. 1) the user can manually select the time duration of the session.Trophotropic response system 9 may then record the temperature of theuser if the user places their finger on the temperature sensor 22.

The user then positions the audio-visual module 12 such that the user'ssenses of sight and sound are subject to the visual and audio signalsprovided by the system 9 after the user presses the GO button 38 (FIG.1). Typically, after the user pushes the GO button 38, the user hearsthe starting binaural beat frequency sound imposed upon pink backgroundnoise. The binaural beat frequency is then decreased at a rate of 2.4Hz/minute, in steps of 0.1 Hz until the ending binaural frequency as setby the user is reached. Once this frequency is reached, this binauralbeat frequency is maintained for the remainder of the session. Duringthe session the LEDs 54 emit light having a frequency and intensityrelated to the binaural beat frequency. For example, the LEDs 54 mayflash at a frequency equal to and in coincidence with the binaural beatfrequency. The binaural beat frequency may be decreased at a ratetypically in the range of about 2.0 Hz/minute to 3.7 Hz/minute. That is,predetermined values may be included in the software such that the rateof change of frequency is different from 2.4 Hz/min, or that the step isdifferent from 0.1 Hz. Each user may prefer a slightly different ratechange. Like wise, the step frequency of 0.1 Hz may typically be variedby about +25 percent. However an optimum rate change is typically about2.4 Hz/minute.

As the session ends, the intensity of the light signal emitted from theLEDs 54 and the intensity of the sound signal provided to the earphones46 is gradually reduced (i.e. is faded out). At the end of the session,the user can again have the system measure finger temperature by placingtheir finger on the temperature sensor 22. A change in temperaturedetected by the temperature sensor 22 may be indicative of a change inblood circulation and thus may provide an indication of how well theuser has achieved the relaxation response. For example, an increase intemperature may indicate the user has achieved a relaxation response. Itshould be noted that the system may operate in a so-calledpre-programmed mode or in a so-called manual mode. In both thepre-programmed and manual modes, the user may select the startingfrequency and the ending frequency.

Furthermore, in the manual mode the user may update the frequencysettings during the session. The system thus allows a user to select thetype of session to be run.

For example, the user may simply press the GO button and the systemexecutes a session for a predetermined period of time (e.g. 15 minutes)with predetermined start and end frequencies. Alternatively, the usermay measure the start and end finger temperatures then go to manual modeand select the start and end frequencies and then begin execution of thesession by pressing the GO button. Alternatively, the user may select amode wherein the user sets the time, presses GO and then is able tomanually set the start and end frequencies.

The functionality described above is controlled by a series ofelectronic components which, in this embodiment, are disposed primarilywithin the resilient plastic housing 40. Those of ordinary skill in theart will recognize, of course that the placement of any or all of suchelectronic components is arbitrary and that all or a portion of theelectronics may be disposed in the audio-visual headset 12, for example.

Referring now to FIG. 9, a block diagram of an embodiment of theelectronic components 89 of the system of the invention is shown. Inthis embodiment, system electronics 89 includes a microcomputersubsystem 90 which receives its instructions from the keypad 28 of thecontrol module 10. In the embodiment shown, the microcomputer subsystem90 includes a microprocessor 100 and an analog-to-digital converter(ADC) 101. The microcomputer subsystem 90 transmits data and controlsignals to the liquid crystal display 20 and LEDs 54 through a displaysubsystem 102. The light intensity of the LEDs 54 is jointly controlledby both the microprocessor 100 and the light intensity control 26.

Similarly the microcomputer 90 transmits audio and control signals tothe earphones 46 of the audio-visual module 12 through an audiosubsystem 104 which includes an amplifier/mixer arrangement. The gain ofthe audio subsystem 104 is determined by a variable resistor 24. Theresistance of the resistor 24 may be adjusted to provide a means forcontrolling the sound level of audio signals fed to the earphone 46.

Power to the system is provided by battery or external power source 110and is regulated by voltage control subsystem 106.

The microprocessor 100 receives user temperature data from thetemperature sensor 22 by way of the analog-to-digital converter 101portion of the microcomputer subsystem 90. Upon the user's placing ofhis or her finger on the temperature sensor 22, the analog dataconverted by the ADC 101 is supplied to the microprocessor 100 foranalysis. The ADC 101 also provides data to the microprocessor 100 fromthe power monitor subsystem 112.

Referring now to FIG. 10, portions of the microcomputer subsystem 90,display subsystem 102, the audio amplifier/mixer 104 and the voltagecontrol subsystem 106 are shown in more detail. The trophotropicresponse system 9 receives power 110 from either a battery connection120 or an external DC power jack 122. The power supply 110 providespower to the microcomputer subsystem 90 through both a power inputterminal 110 and a regulated voltage input terminal VREG 130. A POWERinput terminal 150 of microprocessor 90 is coupled directly to the powersupply 110 (FIG. 9) through voltage control subsystem 106. A voltageregulator 148 disposed in voltage control subsystem 106 provides aregulated voltage to the VREG input terminal 170 of the microcomputersubsystem 90, the VREG input terminal 172 of display subsystem 102 andthe VREG input terminal 174 of the audio subsystem 104.

The system 9 may operate in either a lower power consumption mode or inan on mode. In the low power consumption or "sleep-mode" only themicrocomputer subsystem 90 is supplied power. In the "on mode" aregulated voltage is provided to the entire system 9. The power mode inuse is controlled by a signal line 134 of a parallel output port whichis designated as the power mode (PWR₋₋ MODE) output terminal ofmicrocomputer subsystem 90.

A voltage low signal on the PWR₋₋ MODE output terminal 134 of themicroprocessor subsystem 90 causes an NPN transistor 140 to turn off,thereby turning off a PNP transistor 142. The turning off of PNPtransistor 142 turns off the input power to the system voltage regulator148, permitting the system to enter the power conservation or sleepmode. The directly applied, unregulated, power to the POWER inputterminal 150 of microcomputer 90 permits microprocessor 100 (FIG. 9) ofthe microcomputer subsystem 90 to function thereby permitting the system9 to operate when a user enters data from the keypad 28 (FIG. 1).

Thus, in sleep mode the microcontroller remains powered, in a powerconserving state. Once the system enters sleep mode, the only key thatwill cause the microcontroller to respond is the POWER key 30 (FIG. 1).Once the POWER key is pressed, the microcontroller emerges from sleepmode and can then accept commands from the user input through keypad 28(FIG. 1).

Video data for the LCD display 20 is supplied to the display subsystem102 by the microcomputer subsystem 90 through an 8 bit parallel port152. Display subsystem 102 is coupled to a second 8 bit parallel port ofthe microcomputer subsystem 90. The second 8 bit parallel port includeslines 154-162 which function to provide read enable (/RE) 154, writeenable (/WE) 156, READY 158, and STANDBY 160 signals to the displaysubsystem 102 and control the updating of the LCD display 20.

Additionally, and as will be described in detail in conjunction withFIG. 11 below, a signal having a sinusoidal shape is fed from SINE line164 of the second parallel port to terminal 102g of display subsystem102. Similarly microcomputer subsystem 90 generates a square wave signalSQ₋₋ WAVE at terminal 166, which is fed to terminal 102h of subsystem102.

Likewise, and as also will be described further below, the microcomputersubsystem 90 generates at a third parallel output port a pair of audiosignals designated L₋₋ WAVE and R₋₋ WAVE on signal lines 172, 174. Theleft wave (L₋₋ WAVE) and right wave (R₋₋ WAVE) signals are coupled fromterminals 172, 174 of microprocessor 90 to the audio amplifier/mixersubsystem 104 at terminals 104a, 104b. A FADE signal is coupled frommicrocomputer to both display subsystem 102 and the audioamplifier/mixer subsystem 104.

Signals from two terminals of the microcomputer subsystem 90 areprocessed to generate the left beat (L₋₋ BEAT) 180 and right beat (R₋₋BEAT) 182 signals for the audio mixer/amplifier subsystem 104. Thefunctions of each of these signals are further described below.

Referring now to FIG. 11, in which like elements of FIG. 10 are providedhaving like reference designations, FIG. 11 depicts the microcomputersubsystem 90 in more detail. Microcomputer system 90 includes amicro-controller 300 which may be provided, for example, as the typemanufactured by Motorola Corp. and identified as part number68HC05B4-PLC. Those of ordinary skill in the art will recognize ofcourse that any micro-controller having similar operating features andcharacteristics may also be used.

Microcontroller 300 receives power and a regulated voltage from lines110, 150 respectively as described in conjunction with FIG. 10 above.Microcontroller 300 includes microprocessor 100 (FIG. 9) A/D converter101 (FIG. 9), and a plurality of parallel input/output (I/O) ports PA,PB and PC. Each of the I/O ports include a plurality of I/O terminalsrespectively designated PA0-PC7.

Touch sensor 22, described above in conjunction with FIGS. 1-9, has aninput terminal 22a coupled to input voltage terminal VSW and an outputterminal 22b coupled through a temperature sense circuit 303 to atemperature sense input terminal AN0 of microcontroller 300. Atpredetermined times the controller executes a temperature routine.During the temperature routine, the LCD is updated with the A/Dinformation from temperature sensor 22. Temperature sense circuit 303includes an amplifier 302 having a first input port 302a coupled tosensor 22. An amplifier output port 302c is coupled to microcontrollertemperature sense input terminal AN0. A resistor R68 provides a feedbacksignal path between amplifier output port 302c and a second amplifierinput port 302b. Thus amplifier 302 provides a signal to temperaturesense input terminal AN0 of microcontroller 300.

Input voltage terminal VSW is also coupled through a battery sensecircuit 304 to a battery sense input terminal AN1 of microcontroller300. The battery voltage is checked once before each session. If thebattery voltage is low, an indication is provided on the LCD display.Battery sense circuit 304 is here provided from a capacitor C32 having afirst electrode coupled to the voltage input terminal and a secondelectrode coupled to ground and resistors R52, R53 coupled as shown.Thus via temperature sensor 22 and battery sense circuit 302,microcontroller 300 monitors both the battery voltage and usertemperature and, as described above in conjunction with FIGS. 9 and 10,performs appropriate functions and provides signals in response totemperature and battery sense signals fed thereto.

The microcontroller 300 includes a pair of output signal lines PLMA,PLMB. Each of the output signal lines are coupled to corresponding onesof a pair of amplifiers 306, 308 at respective input ports 306a, 308a.Amplifiers, 306D, 308C have respective output ports 306C, 308c coupledto a first electrode of respective ones of a pair of transistor Q5, Q7.Each of the amplifiers 306D, 308C are also provided having negativefeedback between the respective output ports 306C, 308C and second inputports 306b, 308b.

Microcontroller 300 controls the signal level of each of the audiosignals L₋₋ WAVE, R₋₋ WAVE via the signal levels of signals fed from thepair of control lines PLMA, PLMB to the amplifiers 306, 308. Thus,control line PLMA provides a signal to input port 306a of amplifier306D. Amplifier 306 in turn provides an output signal at output port306d which drives the emitter electrode of the transistor Q7 to providean output signal having a predetermined signal level at the output port172.

Likewise, control line PLMB provides a signal to the amplifier 308 whichdrives the emitter electrode of the transistor Q6 to provide an outputsignal having a predetermined signal level at the output port 174. Thus,the microcomputer system 90 provides a pair of audio output signals L₋₋WAVE and R₋₋ WAVE at respective output terminals 172, 174.

Microcontroller 300 includes a pair of time compare registers havingoutput ports TCMP1, TCMP2 on which a pair of beat signals L₋₋ BEAT, R₋₋BEAT are provided to output ports 180, 182 through respective ones offilters 307, 309. The L₋₋ BEAT and R₋₋ BEAT signals are provided frommicrocontroller 300 as a series of signal pulses. The series of pulsesignals generally resemble a square wave signal. Square wave signals area composite of sinusoidal shaped signals at a base frequency and higherfrequencies. Here, only the base frequency signal is desired. Thusfilters 307, 309 are here provided having a low pass filtercharacteristic. By feeding the L₋₋ BEAT and R₋₋ BEAT signals through lowpass filters 307, 309, substantially all of the higher frequency signalsare removed and only the base frequency signal remains. Furthermore,filters 307, 309 filter out relatively high frequency noise spikes whichmay occur in the signal path and thus prevent such noise spikes frombeing fed to output ports 180, 182.

To provided the signals L₋₋ BEAT and R₋₋ BEAT, the time compare registerare loaded with a value from the processor of microcontroller 300 andthe time compare registers begin to countdown. When the countdown iscomplete the output toggles (e.g. 1 to 0 or 0 to 1) and the countdownstarts again. In TTL logic this corresponds to a pulse train signalhaving voltage levels of substantially 0 volts and substantially fivevolts. Other voltages corresponding to different logic types may ofcourse also be used. Thus, the L₋₋ BEAT, R₋₋ BEAT signals are output onrespective ones of ports TCMP1, TCMP2 of microcontroller 300 and areprovided having alternate values of 0 and 1.

Output ports TCMP1, TCMP2 are also coupled to a pair of input ports310a, 310b of an exclusive-or (XOR) logic circuit 310. XOR logic circuit310 receives the input signals fed thereto on input ports 310a, 310b andprovides an output signal having a sinusoidal shape at output port 310c.

Output port 310c of the XOR logic circuit 310 is coupled to outputterminal 164 through a filter 311 having a low pass filtercharacteristic. Logic circuit 310 provides a sinusoidal output signalSINE to terminal 164 and also provides a high impedance characteristicat terminal 164.

Microcontroller 300 also provides a control voltage compare signal CV₋₋COMP from terminal PA0 of I/O port PA to a first terminal of an RCcircuit 313. A second terminal of circuit 313 is coupled to an amplifier314 at a first input port 314a. A second input port 314b of amplifier314 is coupled to terminal 164 to thus couple a portion of the signalprovided by logic circuit 310 to the first amplifier input port. Whenthe amplitude of the signal provided by microcontroller 300 is greaterthan the amplitude of the signal at input port 314a, amplifier 314provides an output signal at output port 314c having a first signallevel. However, when the amplitude of the signal provided bymicrocontroller 300 to input port 314a is less than the amplitude of thesignal at input port 314b, amplifier 314 provides an output signalhaving a second different signal level. Thus, amplifier 314 provides anoutput signal SQUARE having a square waveform shape at output terminal166.

The control voltage compare signal CV₋₋ COMP fed through the RC circuit313 functions in the manner of a pulse width modulator. The signalprovided at the second terminal of the RC circuit is provided having anaverage DC voltage level corresponding to the amplitude and duration ofthe CV₋₋ COMP signal. Thus the CV₋₋ COMP signal provides a thresholdvoltage to the comparator circuit 314 at input terminal 314a.

When the sign wave coupled to the second input port 314b of thecomparator circuit 314 has a voltage level which is less then thevoltage level of signal CV₋₋ COMP, comparator circuit 314 provides a"low" output signal. However, when the sign wave signal coupled tocomparator input port 314b has a voltage level which is greater than thevoltage level of threshold voltage at comparator input terminal 314a,the output of the comparator circuit is "high." Thus, the comparatorcircuit 314 provides a square wave signal SQUARE at output terminal314c. The frequency and amplitude of the SQUARE wave signal is dependentupon the signals CV₋₋ COMP and SINE.

Microcontroller 300 provides another output signal at A terminal PC3 ofI/O port PC. The output signal is coupled from terminal PC3 through apair of resistive branch arms to a control electrode Q9A of a transistorQ9. The first branch arm includes a resistor R51 and a diode D4 coupledin series between terminal PC3 and the control electrode Q9a. The secondbranch arm includes a resistor R50 connected in series between terminalPC3 and the control electrode Q9a.

A control signal provided from microcomputer output port PC3 controlsthe start-up, ramp-up and the ending fade-out of LEDs 54 and the audiosignal. A resistor R51 is serially coupled between port PC3 and an anodeof a diode D4. A cathode of diode D4 is coupled to a first electrode ofan electrolytic capacitor C29. A resistor R50 is coupled in parallelwith resistor R51 and diode D4. A transistor Q9 has a first electrodeQ9a coupled to the junction of the diode cathode, resistor R50 andcapacitor C29.

Transistor Q9 has a second electrode Q9b coupled to a first referencepotential VREG and a third electrode Q9c coupled to a first electrode ofa variable resistor R100. A second electrode of resistor R100 is coupledto a second reference potential, here corresponding to ground. A thirdelectrode of register R100 is coupled to an output terminal 176. Outputsignal FADE₋₋ LED is coupled from transistor electrode Q9c to the outputterminal 175. Output signal FADE₋₋ AUDIO is coupled from the thirdterminal of resistor 100 to output terminal 176.

The resistance value of resistor R51 and D4 limit the current flow intoelectrolytic capacitor C29 and thus establish a time period during whichcapacitor C29 is charged to a predetermined level. The resistance valueof resistor R50 establishes a decay time by regulating the rate at whichcapacitor C29 discharges. Transistor Q9 provides signal current gain.Transistor emitter Q9b is coupled to variable resistor R100. Theresistance value of resistor R100 may be changed which provides acorresponding change in the value of the FADE₋₋ AUDIO signal.

The FADE₋₋ AUDIO signal controls the amplitude of the sound emitted byearphones 46 (FIGS. 7, 8) such that the sound provided by earphones 46may be gradually increased or reduced (i.e. faded in or faded out)rather than simply being abruptly turned on or off.

The FADE₋₋ AUDIO signal at terminal 176 is coupled to audio subsystem104 (FIGS. 10, 12) at input terminal 104e. The FADE₋₋ AUDIO signal isfed to a pair of bias ports 322a, 322b of a transconducting amplifier322 (FIG. 12). The operation of amplifier 322 will be described furtherbelow in conjunction with FIG. 13. Suffice it here to say that as thevoltage level of the FADE₋₋ AUDIO signal decreases, thus decreasing thebias voltage fed to amplifier 322, the audio signal levels provided byearphones 46 are reduced.

As will be described in conjunction with FIG. 13 below, the FADE₋₋ LEDsignal controls the fade-in and fade-out of LEDs 54 (FIG. 8) such thatthe brightness of the LEDs may be gradually increased or reduced (i.e.faded-in or faded-out) rather than simply being abruptly turned on orturned off. It should be noted, however, that the resistance of variableresistor R98 (FIG. 13) determines the absolute brightness of LEDs 54. Asthe voltage level of the FADE₋₋ LED signal decreases, amplifier 330(FIG. 13) and likewise transistor Q10 (FIG. 13) are gradually turned offto respectively reduce the LED brightness levels.

Referring now to FIG. 12, in which like elements of FIGS. 9, 10 and 11are provided having like reference designations, the audio subsystem 104described above in conjunction with FIG. 9 is here shown to include apair of like left and right audio channels 105a, 105b, each having firstand second pairs of input signal paths along which corresponding ones ofthe L₋₋ BEAT, L₋₋ WAVE and R₋₋ BEAT, R₋₋ WAVE signals are fed from themicroprocessor system 100 (FIG. 12). Signals L₋₋ BEAT, L₋₋ WAVE, R₋₋BEAT and R₋₋ WAVE are fed to a transconductance amplifier 322 atrespective ones of first and second input ports 322a, 322a'. Audiocircuit 104 further includes an external input port J2 to accept astereo input jack. Thus, left and right external signals L₋₋ EXT and R₋₋EXT may also be fed to corresponding ones of the transconductanceamplifier input ports 322a, 322a'.

Such external signals may be provided, for example, from an externalsource such as an analog cassette tape deck, a digital audio cassetteplayer, a compact disc player or the like. Such external signals maycorrespond to music or simply verbal instructions or suggestionsdesigned to aid a user in achieving a trophotropic response.

The transconductance amplifier 322 may be provided, for example, as thetype manufactured by National Semiconductor and identified as partnumber LM13600. Resistors R25, R27 and R28 mix the individual L₋₋ BEAT,L₋₋ WAVE and L₋₋ EXT signals in desired proportions and the signals arecombined at the junction of resistor R18 and input port 322a ofamplifier 322. It should also be noted that capacitor C9 and resistorR26 coupled as shown provide a treble boost to the L₋₋ EXT signal.Transconductance amplifier 322 receives the combined L₋₋ BEAT, L₋₋ WAVEand L₋₋ EXT signals and provides a corresponding output signal on afirst output signal path 322b.

Similarly, resistors R29, R31 and R32 mix the individual R₋₋ EXT, R₋₋BEAT and R₋₋ WAVE signals in desired proportions and the signals arecombined at the junction of resistor R20 and input port 322a' ofamplifier 322. Capacitor C13 and resistor R30 coupled as shown provide atreble boost to the R₋₋ EXT signal. Transconductance amplifier 322combines the R₋₋ BEAT, R₋₋ WAVE and R₋₋ EXT signals and provides acorresponding output signal on a second output signal path 322b'.

The gain of amplifier 322 is set by the current through resistors R23,R24. This current is approximately proportional to the voltage of theFADE₋₋ AUDIO signal provided on input port 104e. The first and secondoutput signals provided from amplifier 322 are fed to respective ones ofa pair of amplifiers 324, 326 at input ports 324a, 326a. Amplifiers 322,324 amplify the signals fed thereto and provide the signals havingappropriate signal levels to a connector J1.

Referring now to FIG. 13, the display subsystem 102 includes an LCDdriver circuit 301 and an LED driver circuit 329. The LCD driver circuit301 includes a random access memory (RAM) and an internal oscillator.The LCD driver circuit 301 may be provided, for example, as the typemanufactured by Hitachi and identified as part number HD61602. The LCDdriver circuit 301 is coupled to the LCD display 20 and uses theinternal oscillator to refresh the display of data on the LCD display 20at a predetermined rate corresponding to the frequency of theoscillator.

The LCD driver circuit 301 receives a plurality of data input signalsD0-D7 on a corresponding plurality of input data lines generally denoted102a. LCD driver circuit 301 also receives from microcontroller 300 aplurality of control signals /WE, /RE, READY and STANDBY on controllines 102b, 102c, 102d, and 102e. When LCD driver 301 provides a READYsignal on output terminal 102d, microcontroller 300 (FIG. 10) providesone or more active signals to LCD driver circuit 301 and LCD drivercircuit 301 performs a corresponding function. For example, when themicrocontroller 300 sends an active write command /WE to the LCD drivercircuit 301, the LCD driver circuit 301 functions to display the data onlines D0-D7 on the LCD display 20. It should be noted that to display asegment, both an address and the data should be passed over the 8-bitbus. Thus two write cycles are required to display data.

The microcontroller 300 also provides SINE, SQ₋₋ WAVE, and FADE₋₋ LEDsignals to the LED driver circuit 329 of the display subsystem 102. TheSINE and SQ₋₋ WAVE signals are coupled to the LED₋₋ DRV signal path 102Rthrough amplifiers 330, 332.

The sinusoidal control signal SINE provided by the microcontroller 300(FIG. 11) at output port 164 (FIG. 11) is fed to subsystem 102 atterminal 102g and is coupled through serial resistor R300 to a firstinput terminal, here corresponding to a negative input terminal, of aninverting buffer amplifier 332. A second input terminal, herecorresponding to a positive input terminal, of inverting bufferamplifier 332 is coupled to a reference voltage V_(REF). Referencevoltage V_(REF) is here provided having a value corresponding to V_(REG)/2. When the amplitude of signal SINE at the first input terminal ofamplifier 332 is greater than the amplitude of V_(REF), then amplifier332 provides an output signal having a first value. When the amplitudeof signal SINE at the first input terminal of amplifier 332 is less thanthe amplitude of V_(REF), then amplifier 332 provides an output signalhaving a second different value.

The output signal from amplifier 332 is fed to a difference input 330aof amplifier 330. Likewise the FADE₋₋ LED and SQ₋₋ WAVE signals arecoupled to amplifier input 330a. An emitter of transistor Q10 is coupledto terminal 102j and is also coupled to amplifier input 330a through aresistor R305.

Amplifier 330 and transistor Q10 form a high current output invertingamplifier which drives LEDs 54 (FIG. 8). The sinusoidally shaped outputsignal SINE from microprocessor 90 (FIG. 10) is coupled throughinverting buffer amplifier 332 to the difference input 330aof driveramplifier 330. The emitter electrode of transistor Q10 is also coupledto this summing junction as is the output terminal of the square wavegenerator provided from amplifier 314 (FIG. 11).

It should be noted that in this particular embodiment fade circuitrygoes low to turn off LEDs 54. That is, when the signal provided at thenegative input terminal 330a of amplifier 330 corresponds to a firstpredetermined value, transistor Q10 is biased into its conduction stateand thus provides a low impedance signal path between terminal 102j andground. When the signal provided at the negative input terminal 330a ofamplifier 330 corresponds to a second predetermined value, transistorQ10 is biased into its non-conduction state and thus provides arelatively high impedance signal path between terminal 102j and ground.Thus the potential on terminal 102j alternates between first and secondvoltages in accordance with the conduction state of transistor Q10. Thiscauses LEDs 54 to turn on and off in accordance with the voltage levelon terminal 102j.

When driver circuit 331 provides square wave signals to the LEDs 54, theoutput of amplifier 330 goes low to pull the driver amplifier differenceinput to ground for most of the cycle (e.g., during the trough of thesine wave--which corresponds to approximately 60 to 70% of the cycle).Although a true square wave is not provided since the signal peaks arerounded, the sharp turn on and turn off of transistor Q10 provides asignal having a substantially pulse wave shape.

LEDs 54 are driven by a sinusoidal signal. The brightness of LEDs 54periodically increase and decrease dependent upon the amplitude of thesinusoidal signal. The frequency of the sinusoidal signal may be variedin frequency from typically 3 HZ to about 30 Hz. Depending upon theparticular operating mode of the system the starting frequency may varyfrom, for example 30 Hz to 3 Hz.

If the binaural beat frequency, and thus the light flash frequency isrelatively slow, less than 11 Hz for example, then the shape of thewaveform driving LEDs 54 is substantially sinusoidal. That is, thesignal waveform driving LEDs 54 is smoothly varying such that LEDs 54turn on and off relatively gradually without any abrupt increases ordecreases in LED brightness. Thus LEDs 54 provide a light pattern whichappears continuous to a user. This results in a preferred appearance toa user at relatively low frequencies.

If the binaural beat frequency and thus the light flash frequency isrelatively fast (e.g. greater than 11 Hz), then it is desirable to driveLEDs 54 with a signal which sharply turns LEDs 54 on and off. Thus atrelatively high light flash frequencies, LEDs 54 are preferably drivenwith a pulse waveform signal. For example, a square wave signal having aduty cycle less than 50 percent may be used.

When binaural beat frequency and thus the light flash frequency reach apredetermined value, 11 Hz for example, then rather than abruptlychanging the signal waveform of the LED drive signal from a sinusoidalwaveform to a pulse waveform, it is preferred to phase in the pulse wavesignal and phase out the sinusoidal waveform signal. Thus, in thisexample, when the binaural beat frequency reaches 11 Hz and increasesabove 11 Hz, a pulse waveform signal is added to a portion of thesinusoidal signal corresponding to the highest portion of the sinusoidalwaveform signal.

As the frequency continues to increase past 11 Hz, the amplitude of thepulse wave signal continues to increase. Furthermore, the amplitude ofthe sinusoidal signal may be reduced such that the pulse waveform signalcharacteristics dominate the sinusoidal signal characteristics. Thesinusoidal signal amplitude may be reduced in a linear or any othermanner such that at 20 Hz the amplitude of the sinusoidal signal issubstantially zero. Thus the sharpness of the LED drive signal waveformis increased which produces a corresponding increase in the sharpness ofthe light pattern provided by LEDs 54.

As mentioned in the above example, the LED drive signal waveformcharacteristic is preferably changed from a sinusoidal waveform shapebelow 11 Hz to a pulse waveform shape at about 20 Hz. This selection ofdrive waveform shape may of course be modified to provide any desiredlight pattern. For example, in some applications it may be desirable toprovide the LED drive having a sinusoidal waveform shape below 6 Hz anda pulse waveform shape at about 14 Hz.

Transistor Q10 increases the current drive of operational amplifier 330.This allows a proportional drive signal to be fed to LEDs 54. That is, aproportional current is fed to LEDs 54 and the LEDs 54 are not abruptlyturned on and off. Thus, if the voltage level of the FADE₋₋ LED signalis increased or decreased, the brightness of LEDs 54 changesproportionately. Similarly, as the voltage level of the SINE signalincreases or decreases the brightness of LEDs 54 changesproportionately. The SQUARE signal operates to effectively turn on andoff the SINE signal. The FADE₋₋ LED signal works as an override signal,limiting the brightness of LEDs 54 due to the sine and square wavesignals.

FIGS. 14-14D show a series of flow diagrams of the processing performedin the microcomputer 90 (FIG. 10) of the control module 10 (FIGS. 1-6)to provide output and control signals to the display 20 (FIG. 1) and theaudio visual module 12 (FIG. 7).

In the flow diagram, the rectangular elements (typified by element 402)herein denoted "processing blocks" represent computer softwareinstructions or groups of instructions. The diamond shaped elements(typified by element 408) herein denoted "decision blocks" representcomputer software instructions or groups of instructions which affectthe execution of the computer software instructions represented by theprocessing blocks. The flow diagram does not depict syntax or anyparticular computer programming language. Rather, the flow diagramillustrates the functional information one skilled in the art requiresto generate computer software to perform the processing required ofcontrol module 10. It should be noted that many routine program elementssuch as initialization of registers, loops and variables and the use oftemporary variables are not shown.

Turning now to FIG. 14, processing block 402 performs a firstinitialization procedure upon initial power up of the system.Initialization routine 402 is performed only once when power isinitially supplied to the unit (e.g when batteries are initially placedin the unit). During the initialization procedure, parameters includingbut not limited to microcomputer 90 output terminals, the temperatureoutput ports, the liquid crystal diode (LCD) display 20 and allmicrocomputer interrupt masks are cleared. The external interrupt modeof microprocessor 300 is enabled and the control module 10 (FIGS. 1-6)is placed in the power on mode.

In processing block 404, a second initialization procedure is performed.In the second initialization procedure the direction (i.e. inputs oroutputs) of the bi-directional data ports of microprocessor 300 are setand the microprocessor registers are initialized. The secondinitialization procedure 404 is performed whenever the system emergesfrom the so-called "sleep mode" or power conservation mode. When thesystem emerges from sleep modes the operation of the LCD display 20 isverified and a predetermined set of information is displayed. Suchinformation may, for example, correspond to default start and endfrequencies and a default session time.

As show in processing block 406 a third initialization procedure occursduring which the keyboard is scanned and variables are set according toparticular keys on the keyboard which have been actuated. Also anoverflow check is performed and the current information stored in themicroprocessor 300 is updated and displayed on LCD display 20.

Processing begins in the Edit Mode with decision block 408. In decisionblock 408, when the GO button 38 (FIG. 1) is pressed then the processingleaves the Edit Mode and flows to the Run Session mode as shown inprocessing block 410. The Run Session mode will be described below indetail in conjunction with FIGS. 14A-14B. Suffice it here to say that inthe Run Session mode a decision is made as to whether the system willoperate in a so-called Pre-programmed Mode or a Manual Mode.

Until the GO button 38 is pressed processing continues in the edit todecision block 412. In response to a any key on key pad 28 (FIG. 1)being pressed program parameters and LCD display 20 are updated. If nokey is pressed, processing continues to decision block 416 where adetermination is made as to whether a starting temperature was taken.

The determination is made by examining a flag TEMP₋₋ DONE which is setto zero if the starting temperature of the user has not been taken andset to one if the user's starting temperature has been taken. The TEMP₋₋DONE flag is set in response to a finger being placed on the temperaturesensor 22 (FIG. 1). Thus, the user's starting temperature is taken onlyonce.

If the TEMP₋₋ DONE flag is not set, then processing continues todecision block 418 where the system determines whether a user wants tohave finger temperature measured. This determination may be accomplishedfor example by examining a bit on input port and of microprocessor 300which indicates whether a contact switch coupled to sensor 22 is engagedindicating that the user has placed a finger on temperature sensor 22.If there is an indication that a request for temperature has been made,then processing continues to processing block 420 where the user'sfinger temperature as measured by temperature sensor 22 is stored in amemory location of microprocessor 300.

Regardless of whether the starting temperature was taken, processingcontinues to decision block 422 where microprocessor 300 determines if apredetermined amount of time has passed without the microprocessorreceiving any keyboard inputs. The predetermined amount of time maycorrespond for example to 120 seconds. Time periods longer or shorterthan 120 seconds may of course also be used. If the predetermined periodof time has passed without any keyboard inputs, then processing loopsback to decision block 408 where decision is made to leave the editmode. Every time a key is touched or a temperature is taken, the timeout counter is reset to zero. When no inputs have been received and GObutton 38 has not been pressed to start the session, the time outcounter continues to count.

If no buttons have been pressed for a predetermined period of time thena so-called time out occurs and processing continues to decision block428 where a determination is made as to whether a session was completed.If a session was not completed then processing continues to processingblocks 444 and 446. In processing block 444 an LCD display test isperformed. The LCD display test may include, for example, the step offlashing the LCD display twice. The LCD display test indicates that thesystem is about to enter a power conservation mode.

After the LCD display test, processing continues to processing block 446in which the system enters a power conservation mode which may bereferred to as a so-called "sleep mode." In the power conservation mode,microprocessor 300 terminates power to substantially all other powerconsuming devices such as other integrated circuits and the like. Themicroprocessor itself then enters a power conservation mode and butremains powered on and monitors signals provided from external inputs,interrupts and the like. It may be possible to place other devicesbesides microprocessor 300 in a sleep mode rather than totally removingpower from the devices. If an interrupt or other input signal isreceived, microprocessor 300 emerges from the sleep mode and reactivatesthe control module circuitry and processing begins again ininitialization step 404.

If in decision block 428 a decision is made that a session has completedthen a fade out routine is performed as shown in processing blocks430-434. During fade out step 430 the brightness of LEDs 54 (FIG. 8) aregradually reduced as is the sound level provided from earphone 46. Inprocessing block 432 noise values are updated and in processing block434 a wave envelope amplitude is decreased. The noise values and thewave envelope will be described further below in conjunction with FIGS.14A-14D. Suffice it here to say that such signals are generated toprovide an appropriate audio environment to a user.

After the fade out is complete, the system determines whether a startingtemperature was taken in decision block 436. If a starting temperaturewas not taken then system performs the LCD display test and enters thepower conservation mode as shown in steps 444 and 446. If a temperaturewas taken at start of session in processing block 420 then it would bedesirable to compute any change in temperature which occurred as aresult of completing a session since this may be an indication that atrophotropic response was achieved. Thus if a starting temperature wastaken, processing continues to a temperature request routine as shown instep 438.

If a request is made to take a final temperature then a finaltemperature is taken as shown in step 440. A user makes a request fortemperature by placing a finger on temperature sensor 22. If no requestto take a final temperature is made then processing continues todecision step 442 which implements a loop to wait a predetermined periodof time. If no request to take a final temperature is made within thepredetermined period of time, the processing continues to the LCDdisplay step 444 and power conservation mode step 446.

Referring now to FIG. 14A, when GO button 38 is pressed, processingflows to the Run Session mode. In the Run Session mode processing mayoccur in either the so-called Pre-programmed Mode or the so-calledManual mode. Manual Mode processing will be described in conjunctionwith FIGS. 14C-14D.

Upon entering the Run Session routine, as shown in processing block 450microprocessor timer registers are loaded with predetermined values.Depending upon the values which the session parameters have assumed uponinitial start up, a predetermined time corresponding to the time betweeneach signal update is loaded into the timer registers. Thus for example,if a starting frequency corresponds to 20 Hz then a predetermined periodof time exists between each event which must be done to maintain thefrequency of 20 Hz. Thus the time between each update may be computed orlooked up in a table and loaded into the timer register.

Processing then continues to processing block 452 where a fade-inroutine is performed. During fade-in step 452 the audio and visualsignals provided by system 9 are initially provided to the user atrelatively low amplitude levels.

Processing then continues to decision block 454 where a decision is madebased on whether the user is operating in manual mode. If the system isoperating in manual mode then processing flows to the manual modeprocessing steps described in conjunction with FIGS. 14B, 14C as shownin processing block 456. If the system is not operating in manual modethen processing continues in processing block 458 where noise parametersare updated.

Processing then continues to decision block 460 where decision is madeconcerning the computation of new envelope values. The frequency of thebinaural beat signal is changing at a predetermined rate herecorresponding to a rate of 2.4 Hz/minute. Thus, a change in frequency of0.1 Hz occurs every 2.5 seconds. Therefore, every 2.5 seconds, thesystem must re-calculate the timer values. Consequently, in decisionblock 460 a determination is made as to whether 2.5 seconds has elapsed.If decision is made to compute new envelope values, then processingflows to processing block 462 where new envelope values are computed.

As mentioned above, the trophotropic control module 10 generates signalscorresponding to both aural and visual signals. The aural signal mayinclude an ocean signal component, a binaural beat or sinusoidal signalcomponent, and an external signal component. The visual and auralsignals are related by the binaural beat frequency signal component in amanner which will be described in detail further below.

Each component of the aural signal is fed to the mixer/amplifier stage.The relative amplitudes of the aural signal components are pre-set andmay be expressed as a ratio. For example, one possible amplitude ratioof binaural beat signal component to ocean signal component to externalsignal component may be provided as a voltage ratio 1:6:6. It should benoted of course that the amplitude of the external signal may beadjusted independently of the binaural beat and ocean signal components.

Other ratios may of course also be used. In general, however, the oceansignal component is preferably selected having an amplitude greater thanthe amplitude of the binaural beat signal component such that thebinaural beat signal component may not be an easily identifiable portionof the aural signal. Similar considerations are used when selecting therelative amplitude of an external signal component which may optionallybe used. The particular relative amplitudes of the binaural beat signal,ocean signal and external signal components may be selected inaccordance with a variety of factors including but not limited to thepersonal preference of a particular user.

The binaural beat signal is typically provided as a sinusoidal signalfed to each channel of the mixer/amplifier circuit. The frequency of thebinaural beat signal varies dependent upon which audio channel thebinaural beat frequency signal is fed to.

For example, the binaural beat signal fed to a first audio channel forexample the left audio channel may be provided having a fixed frequencygenerally in the range of about 50-150 Hz. However, the binaural beatsignal fed to a second different audio channel, for example the rightaudio channel, may be provided having a frequency which varies such thatthe frequency of the right side binaural beat signal corresponds to theleft channel frequency plus the binaural beat frequency.

The binaural beat signals should be provided having a harmonic contentsuch that the third harmonic is provided having a signal level less thanor equal to 5% of the power level of the fundamental frequency signal,the fifth harmonic is provided having a signal level less than or equalto 3% of the power level of the fundamental frequency signal and allhigher harmonics are provided having signal power levels less than orequal to 1% of the signal power of the fundamental frequency signal.

The aural signal further includes a so-called ocean signal componentwhich may be provided for example as a random noise signal with aspectrum level having a negative slope of 10 decibels per decadegenerally referred to as pink noise. The pink noise signal is modulatedthrough a pair of so-called envelope signals as will be describedfurther below. Suffice it here to say that the pink noise in eachchannel is generated separately but is provided having the substantiallyequal amplitudes which may be computed according to Equations 1 and 2below.

    Left Channel Amplitude=[D*(E-1/2)+1/2]*N(left)             Equation 1

    Right Channel Amplitude=[D*(1/2-E)+1/2]*N(right)           Equation 2

in which:

E corresponds to a value of a periodic signal having a triangular waveshape and having a minimum value and a maximum value wherein thetriangle wave is generated in a triangular wave generator in themicroprocessor;

D corresponds to a value of a periodic signal having a triangular waveshape and having a minimum value and a maximum value wherein thetriangle wave is generated in a triangular wave generator in themicroprocessor;

N(left) corresponds to the left channel pink noise amplitude; and

N(right) corresponds to the right channel pink noise amplitude.

Equations 1 and 2 show the relation between the time dependent loudnesson the left channel and the time dependent loudness on the rightchannel. The terms N(left) and N(right) give the ocean wave sound asense of direction which appears to move left and right in space.

E and D are variables having values in some discrete range. The portionof the equations 1 and 2 corresponding to the terms [D*(E-1/2)+1/2] and[D*(1/2-E)+1/2] respectively may be calculated inside themicrocontroller and provide the left and right channel amplitudes. Aftercomputing the value, the microcontroller provides a corresponding analogsignal for each of the left and right channels on output ports of theD/A converter (DAC). The analog signals provided by the DAC have voltagelevels corresponding to the respective computed values and may forexample, be in the range from 0 volts to 5 volts. Thus, the terms[D*(E-1/2)+1/2] and [D*(1/2-E)+ 1/2] determine the overall loudness ofthe ocean wave signal and the direction in which the ocean wave signalappears to move in.

It should be noted that the terms N(left) and N(right) correspond tonoise signals and are provided having values of logic 1 or 0 to thusrapidly turn the left and right channel amplitudes on and off.

The terms [D*(E-1/2)+1/2] and [D*(1/2-E)+1/2] provide values whichmodulate the N(left) and N(right) values. That is, the values computedby the terms set an envelope on the N(left) and N(right) audio noisesignals.

The terms [D*(E-1/2)+1/2] and [D*(1/2-E)+1/2] provide complementaryloudness values that modulate the left and right sound and this givesthe apparent ocean wave direction. E has a faster period and drives theocean waves. That is, as E varies over a complete cycle the user hearsthe ocean sound coming towards him and then hears the sound recede.Where this happens in the cycle depends on the value of D.

The function of D is to slowly rotate the overall ocean wave sound. Thatis a user may, for example, hear ocean waves which appear to originatefrom the user's left and after a predetermined period of time the oceanwaves appear to originate from the user's center and after anotherpredetermined amount of time the waves appear to come from the user'sright. Thus, for some values of D the ocean waves appear on the leftside and move toward the right as the sound increase. The ocean wavesthen recede back toward the right. For other values of D the ocean wavesappear to come from the right side of the user, move toward the user'sleft and then recede back to the right.

For example, when E assumes its minimum value then the sum of loudness(Left Channel Amplitude+Right Channel Amplitude) is generally at itslowest value. On the other hand when E assumes its maximum value thenthe sum of the loudness (Left Channel Amplitude+Right Channel Amplitude)is generally at its highest value. The convolution of D and E is suchthat sum of D and E affects balance between the left and right audiochannels. That is, if D and E sum to one value then the balance ismostly left. However, if D and E sum to a second, different value thenthe balance is mostly right.

For example, if the sum of D and E is positive then the balance betweenthe left and right channels may be biased substantially to the left. Ifsum of D and E is negative then the balance between the left and rightchannels may be biased substantially to the right. Consequently, becauseD is slowly varying and thus is approximately constant through a singleocean wave and because the ocean wave loudness generally increases asthe value of E increases, a user may hear the ocean wave come in fromthe left and move toward the right as E assumes larger values. As thevalue of E decreases, the user hears the ocean wave get softer and hearsthe ocean wave receding back toward the left because the sum of D and Eis about the same as when E started out at its minimum value at thebeginning of the wave, increased to its maximum value and returned toits minimum value at the end of the wave. That is, since the value of Ddoes not change substantially then E has a greater impact.

As D slowly changes to a new value, that will change how this waveaffects the left/right balance. That is, the ocean wave sound willeventually appear to come from the right side and move toward the leftand then recede back toward the right side. Thus one of the signals (E)controls the overall instantaneous loudness (i.e. the loudness of thesum of the two signals) and the other signal (D) as the slowly varyingparameter, controls the way in which E affects left right balance. Thus,the value of D determines whether a loud sound should appear to comefrom the user's left side and soft sound toward the user's right side orvice-versa.

The D waveform may be provided having a period of about 100 or 200seconds. The E waveform corresponds to the individual ocean waves andhas a faster period than D. Here, E and D are each provided as trianglewaves. However, it should be noted that E and D may also be providedhaving a sinusoidal wave shape. It has been found however that trianglewave shapes give a preferred sound. It should also be noted that theperiod of triangle wave E can be set to vary with the frequency of thebinaural beat signal.

As mentioned above, the first envelope designated "E" may be provided,for example, having a triangular waveform shape and having a signalperiod which varies linearly in accordance with the frequency of thebinaural beat signal. For example, if the binaural beat signal frequencycorresponds to 20 Hz, the period of the first envelope signal E shouldcorrespond to about 6 seconds. Alternatively, when the frequency of thebinaural beat signal is 1 Hz, the period of the first envelope signal Eshould correspond to about 12 seconds.

The values of 6 and 12 seconds were empirically determined. In general,however, the period of the ocean wave signal is selected to be shorterat high light flash frequencies. This selection is made because userexcitation should be occurring at higher light flash frequencies. Userrelaxation, on the other hand, should be occurring at the lower lightflash frequencies. Thus at the lower light flash frequencies, the oceanwave period should be somewhat longer than the ocean wave period at thehigher light flash frequencies.

Thus, the first envelope signal "E" is provided having a triangularwaveshape and a value typically in the range of about a minimum value0.05 and a maximum value of about 1.0. The second envelope signal "D"may also be provided having a triangular wave shape and may be providedhaving a period typically of about 100 seconds and maximum and minimumvalues respectively typically in the range of about -0.8 to +0.8.

The aural signal may also include a signal component provided from anexternal source. The external source may correspond for example to auser specified stereo audio input having a preset gain which may be feddirectly to the mixer on the audio system. The relative volume of theexternal input may be controlled at the source of the external input.

The binaural beat frequency initially corresponds to a start frequencywhich may be provided as a default value or may be a value provided bythe user. The frequency of the binaural beat signal changes at apredetermined rate which may, for example, correspond to a change of 2.4Hz/minute until the binaural beat signal component frequency reaches anend frequency, which may also be provided either as a default value oras a value set by the user. Once the end frequency is reached, thefrequency of the binaural beat signal remains constant.

The binaural beat frequency changes with a frequency step whichtypically is less than or equal to 0.1 Hz. The frequency step isselected such that the microprocessor provides a smooth sound. Those ofordinary skill in the art will recognize of course that other frequencysteps may also be used.

The visual signal may be provided having any amplitude between first andsecond predetermined amplitude values. Thus the visual signal may beprovided having any amplitude value between 0 and 100% of apredetermined maximum signal amplitude. The amount of light provided bythe LEDs 54 will depend of course on the particular type of LEDs whichare used.

The visual signal may be provided having a frequency which correspondsto a multiple of the frequency of the binaural beat signal. In apreferred embodiment, the visual signal is provided having a frequencywhich equals the frequency of the binaural beat signal.

The visual signal may be provided having a plurality of signalcomponents. For example, the visual signal may be provided from asinusoidal signal fed through a filter having a low pass filtercharacteristic with a 3 decibel (dB) cutoff frequency typically of about8 Hz and a pulse wave having a predetermined duty cycle and an amplitudewhich changes linearly between a first predetermined frequency to asecond predetermined frequency. In a preferred embodiment, for example,the pulse wave may be provided having a 20% duty cycle and an amplitudewhich increases from a predetermined minimum value below 9 Hz to apredetermined maximum value at 20 Hz and above.

For example, below 4 Hz, the LEDs can be driven with a pure sine wave.Between 9 and 20 Hz, the pulse wave duty cycle changes gradually. Above20 Hz, the duty cycle remains steady. The sine wave amplitude diminishesas the frequency increases due to damping by the low-pass filter. Thusthe pulse wave becomes a greater component of the signal as frequencyincreases.

Alternatively, the pulse wave may be provided having a 20% duty cycleand an amplitude which decreases from a predetermined maximum valuebelow 9 Hz to a predetermined minimum value at 20 Hz and above.Alternatively still the pulse wave signal may be provided having apredetermined amplitude and a duty cycle which increases from 0% atfrequencies below 9 Hz to 20% at frequencies of 20 Hz and above. Oralternatively still, the pulse wave signal may be provided having aconstant amplitude and a duty cycle which decreases linearly from 20% atfrequencies below 9 Hz to 0% at frequencies of 20 Hz and above.

The first envelope signal E is updated by a FREQ₋₋ FUNCTION, whichupdates envelope signal E every 0.1 Hertz (Hz). The updated envelopsignal results in a new change for the BEAT frequency. Similarly, thesecond envelop signal D is set with the counter-overflow in the TIME₋₋OV function. Thus the second envelop signal D is updated every time thecounter produces an overflow. In this embodiment, an overflow occursevery 131 milliseconds (64K*2 microseconds). Processing then continuesto processing block 442 where noise values are computed and updated.

If in decision block 460 decision is made not to compute new envelopevalues, then the program flows directly to processing block 464 wherenoise values are updated.

Processing then continues to decision step 468 where the value of thetimer/counter is compared with the duty cycle control time. If thetimer/counter value is greater than the duty cycle control time then asshown in processing block 470 the duty cycle output signal is set low.If the timer/counter value is less than the duty cycle control time thenthe duty cycle output signal is set high as shown in processing block472. As described above in conjunction with FIG. 11 a square wave signalis generated from a sinusoidal signal. Thus, the input signal CV₋₋ COMPfed to comparator 314 (FIG. 11) is toggled between the high and lowstates to create a square wave output signal at comparator output port314c.

The CV₋₋ COMP signal is toggled via a free running counter inmicroprocessor 300. The free running counter here has a cycle time of130 milli-seconds (msecs). Thus, if the timer is set at 65 msec, forexample, then if less than 65 msec has elapsed the duty cycle outputsignal is set low. If more than 65 msec has elapsed then duty cycleoutput signal is set high. Thus, in this example, a signal having a 50%duty cycle is provided.

Processing then continues to processing block 474 where the noise valuesare updated and on to decision block 476 where it is determined whetherthe frequency update window is open. The frequencies are updatedperiodically. Thus, after a predetermined amount of time has elapsed thefrequencies should be updated.

A time "window" about this predetermined time period may be selected.Within this frequency update window the new frequency routine may beenabled. The window of time may correspond to the predetermined timeperiod plus or minus 0.1 seconds. Thus, when decision block 476 isprocessed if an elapsed period of time within 0.1 seconds of thepredetermined period of time has occurred, then processing continues toprocessing block 478 where the new frequency routine is enabled.Processing then flows to processing block 484 where the noise values areupdated.

If the frequency update window is not open then processing flows fromdecision block 476 to decision block 480 where the elapsed time iscompared to a time to toggle the liquid crystal diode display. If it istime to toggle the LCD display then processing continues to processingblock 482 where the LCD display is toggled and processing then flows toprocessing block 484 where the noise values are updated. The LCD displayis toggled after a predetermined period of time has elapsed. Forexample, the LCD toggle may occur every 0.5 seconds. Other predeterminedperiods of time may also be used. Processing then continues to decisionblock 486 where a decision is made as to whether the envelope E valueshould be updated. As describe above, one of the components of thecomputed envelope is designated E. Since E is a component of theenvelope, when E changes the envelope changes. It takes a relativelylarge period of time to calculate the new envelope. At this particularprocessing point however, the processor does not typically havesufficient time to perform the calculations due to other actions beingperformed. Thus rather than calculating the envelope at that particularmoment in time, the system is enabled to perform a new calculation.

The new envelope is calculated when the processor has time to make sucha new calculation. Thus in step 460 when a determination is made ifthere are new parameters, the answer will be yes and at that point intime the processor has time to make the calculations.

If decision is made in step 486 to update E then processing continues toprocessing block 488 where the E value is updated, counters are updatedand the new envelope parameter is enabled. If decision is made not toupdate E then processing flows to processing block 490 where the noiseis updated.

In decision block 492 if the new frequency routine is enabled thenprocessing flows to decision block 494. If the new frequency routine isnot enabled then processing flows back to processing block 458 and noisevalues are updated.

In decision block 494 a decision is made as to whether the counters arewithin a predetermined tolerance value. If the counters are withintolerance then processing flows to processing block 496 where frequencyvalues are updated and noise values are updated as shown in processingblock 498. If in decision block 494 counters are not within tolerancethen processing again flows back to processing block 458. After updatingnoise values as shown in processing block 498, processing continues todecision block 500 where decision is made as to whether a predeterminedperiod of time has elapsed. The predetermined period of time may beselected to be five minutes for example, of course, other time periodsmay also be used. If the predetermined period of time has elapsed thenprocessing continues to processing block where the liquid crystal diodedisplay and counter are updated. If the predetermined period of time hasnot elapsed then processing flows back to processing block 458. Indecision block 504 decision is made as to whether a session hascompleted. If a session has completed, then processing continues todecision block 506 where decision is made as to whether the "AFR" modeis set. If the AFR mode is not set then processing continues to the mainroutine as shown in processing block 508. If however, the AFR mode isset then the AFR mode is enabled as shown in processing block 510 andprocessing returns to processing block 458. By setting the AFR mode,regardless of the end frequency which is selected, the session continuesfor an additional predetermined period of time during which the lightand sound frequencies are set to predetermined levels. For example thelight and sound may be set to frequencies, such as 13 Hz for example,which provide an environment in which a user enters an awakened state.

Referring now to FIGS. 14C and 14D, processing steps in the manual modeare shown. Steps in Manual Mode processing are similar to Pre-programmedMode processing steps. In the Manual Mode however, noise signals areupdated as shown in processing block 512 and then a decision is made asto whether new envelope parameters exist as shown in decision block 514.

If new envelope parameters exist then a new envelop is calculate in step516 and processing then continues to step 464' where noise values areupdated. Processing then flows to steps 468'-510' which aresubstantially the same as steps 468-510 described in conjunction withFIGS. 14a, 14B above.

If new envelope parameters do not exist then processing flows to step518 where it is determined whether the keyboard has been enabled. If thekeyboard has been enabled then a determination is made as to whether akey has been pressed as shown in step 520. In manual mode no startingand ending frequencies exist as in pre-programmed session. Rather inmanual mode only a default starting frequency exists. The user mayselect and change the frequencies of the visual and audio signals duringthe session by entering values from the keyboard. Thus, if a key hasbeen pressed then LCD and parameters are updated as shown in step 522and the program flows to steps 464'-510'. If a key has not been pressedthen step 522 is omitted. Processing then flows to steps 468'-510' asdescribed above.

Having described preferred embodiments of the invention, it will nowbecome apparent to one of skill in the art that other embodimentsincorporating the concepts may be used. It is felt, therefore, thatthese embodiments should not be limited to disclosed embodiments butrather should be limited only by the spirit and scope of the appendedclaims.

We claim:
 1. A trophotropic response system comprising:a control modulefor providing a visual signal and an aural signal, wherein the auralsignal includes at least a digitally generated ocean signal componentand a binaural beat signal component; an audio unit for receiving theaural signal from the control module; and a visual unit for receivingthe visual signal from the control module wherein the visual signal isprovided having a frequency corresponding to the frequency of thebinaural beat signal component of the aural signal, wherein said visualsignal is provided from a sinusoidal signal having a firstpre-determined frequency and a rectangular wave signal having apredetermined duty cycle, wherein the duty cycle of said rectangularwave signal increases monotonically from a first duty cycle at a firstpredetermined frequency to a second different duty cycle correspondingto the predetermined duty cycle at a second predetermined frequency. 2.The trophotropic response system of claim 1 wherein:the binaural beatfrequency begins at a first pre-determined frequency and changes at apre-determined rate until the binaural beat frequency reaches an endfrequency.
 3. The trophotropic response system of claim 2 wherein:theaural signal includes a first signal component and a second signalcomponent wherein the relative amplitudes of the aural signals arepre-set and wherein the voltage amplitude ratios for the first andsecond are provided as 1:6:6.
 4. A trophotropic response systemcomprising:a control module for providing a visual signal and an auralsignal, wherein the aural signal includes at least a digitally generatedocean signal component and a binaural beat signal component; an audiounit for receiving the aural signal from the control module; and avisual unit for receiving the visual signal from the control modulewherein the visual signal is provided having a frequency correspondingto the frequency of the binaural beat signal component of the auralsignal, wherein the aural signal comprises:a binaural beat signalcorresponding to a sign wave signal wherein a first binaural beat signalprovided on a left channel of the audio unit is provided having afrequency typically in the range of about 50-150 Hz and wherein thefrequency of the binaural beat signal on a right channel of the audiounit corresponds to a varying frequency equal to the left channelfrequency plus the binaural beat frequency.
 5. The trophotropic responsesystem of claim 4 wherein:the aural signal further comprises an oceansignal corresponding to noise modulated by a pair of envelope signals,wherein when the amplitude of a first one of said pair of envelopesignals substantially determines an overall loudness of signals on theleft and right channels of the audio unit, the amplitude of a second oneof said pair of signals substantially determines the relative loudnessof the left and right channels and wherein the noise in each of the leftand right channels is generated separately but is provided having thesame amplitude.
 6. The trophotropic response system of claim 5wherein:the first envelope signal is provided having a triangular waveshape with a frequency which varies correspondingly with the binauralbeat frequency; and the second envelope signal is provided having atriangular wave shape and is provided having a predetermined frequency,wherein the frequency and amplitude characteristics of the secondenvelope signal alters the way the first envelope signal affects thestereophonic balance of said left and right channels.
 7. Thetrophotropic response system of claim 6 wherein:the aural signal furthercomprises an external input signal corresponding to a user specifiedstereo audio input having a pre-set gain wherein the relative volume ofthe external input signal is controlled at the source of the externalinput.